Is formulated for maximum resistance to heat, weather, UV and ozone resistance. 23677 Double Wire Corrugated Exhaust Hose - 252 Series2-1/2 x 12-1/2' In addition, the corrugated construction with double wire helix embedded between two rayon spiral cords provides excellent strength and flexibility.. Meets or exceeds SAE J2006 R2 standard, and has double the ozone resistance required by the SAE J2006 standard.